It is said that Sounkyo was first discovered by Ainu people that is the indigenous of Hokkaido. The saying goes that when they were hunting along the Ishikari River, they ran after a brown bear till they climbed up the alpine zone of Mount Taisetsu.
Matsuda Ichitaro worked as Common foot soldier at Ishikari in 1857 ( Ansei 4), as the first Japanese who visited the Ishikari River and studied the water sources there. And he found the hot spring at that time.
Next year, Takeshiro Matsuura was hired as Hakodate magistrate's officer who also named the place as “Hokkaido”, he made his way upstream the Ishikari River till the Aibetsu town , but he did not arrive at Sounkyo. However, the first person listed in the "upstream spa (spa Sounkyo)" on the map of that time is Matsuura. In Taisyo 4 (1915), Mizujiro Shioya built hot spring accommodation and named it Shioya Onsen.
Omachi Keigetsu, the great writer of Meiji named this village as “Sounkyo” when he stayed at Shioya Onsen in 1921 (Taisyo 10). The origin of the name is Ainu people called this village in the region “Souunbetsu” at that time. It means “many waterfall rivers” in their language. Keigetsu was a good walker to climb up to Asahidake Tenninkyo from Kurodake. He left the well-known saying as "Don’t talk about the height of the mountain before you climb up Fuji Mountain. Don’t talk about the spacious of the mountain before you climb up Taisetsu." later.
The entrance of Momijidani back of Sounkyo is the source of the hot spring,, and there are more than 20 gushing points at the range of 200m×100m.The hot spring temperature is over 70 centigrade and its quality belongs to the simple transparent spring.